2. Academic Validation
  3. Low-intensity pulsed ultrasound activates autophagy in periodontal ligament cells in the presence or absence of lipopolysaccharide

Low-intensity pulsed ultrasound activates autophagy in periodontal ligament cells in the presence or absence of lipopolysaccharide

  • Arch Oral Biol. 2020 Sep;117:104769. doi: 10.1016/j.archoralbio.2020.104769.
Yao Li 1,  Chengjun Sun 2,  Ge Feng 3,  Yao He 1,  Jie Li 1,  Jinlin Song 4
Affiliations

Affiliations

  • 1 College of Stomatology, Chongqing Medical University, PR China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, PR China; Chongqing Municipal Key Laboratory of Oral Biomedical Engisneering of Higher Education, PR China.
  • 2 Stomatological Hospital, Southern Medical University, PR China.
  • 3 College of Stomatology, Chongqing Medical University, PR China.
  • 4 College of Stomatology, Chongqing Medical University, PR China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, PR China; Chongqing Municipal Key Laboratory of Oral Biomedical Engisneering of Higher Education, PR China. Electronic address: [email protected].
PMID: 32599516 DOI: 10.1016/j.archoralbio.2020.104769
Abstract

Objective: This study aims to determine if low-intensity pulsed ultrasound (LIPUS) activates Autophagy in human periodontal ligament cells (PDLCs) irrespective of lipopolysaccharide.

Design: Six groups were designed: control, LIPUS, lipopolysaccharide, LIPUS + lipopolysaccharide, LIPUS+3-Methyladenine, LIPUS + lipopolysaccharide+3-Methyl- adenine. LIPUS pretreated PDLCs for 2 h and lipopolysaccharide treated for different times. Real-Time PCR and Western-blot were performed to evaluate mRNA and protein expression levels of autophagic genes Beclin-1 and LC3 respectively. A transmission electronic microscope was used to observe the autophagosome. ELISA was used to test interleukin-6 expression.

Results: Compared with the non-treatment, LIPUS pretreatment increased mRNA expression levels of LC3 (P < 0.05) and Beclin-1 (P < 0.05) at 4 h and 8 h, and enhanced the protein expression levels of LC3-Ⅱ at 8 h (P<0.05) and Beclin-1 at 4 h, 8 h and 16 h(P<0.05). After LIPUS pretreatment and lipopolysaccharide treatment for 8 h, LC3-Ⅱ and Beclin-1 protein expression levels were elevated (P < 0.05) compared with the control. Following further treatment by 3-Methyladenine, Beclin-1 protein expression was decreased (P < 0.05) compared with the LIPUS plus lipopolysaccharide group, but LC3-Ⅱ protein expression was not. Autophagosomes were not found in the LIPUS+3-Methyladenine and LIPUS+lipopolysaccharide+3-Methyladenine groups. After LIPUS pretreatment and lipopolysaccharide treatment for 36 h, intreleukin-6 expression was decreased (P<0.05) compared with the lipopolysaccharide group. However, after addition of 3-Methyladenine, intreleukin-6 expression was elevated (P < 0.05) compared with the LIPUS +lipopolysaccharide group.

Conclusions: LIPUS can promote Autophagy in PDLCs irrespective of lipopolysaccharide. Autophagy might be involved in LIPUS anti-inflammatory mechanism in PDLCS.

Keywords

Autophagy; Interleukin-6; Lipopolysaccharide; Low-intensity pulsed ultrasound; Periodontal ligament cells.

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